Exhaust manifold for radial-cylinder internal-combustion engines



Apnl 26, 1932.- A. H. R. FEDDEN EXHAUST MANIFOLD FOR RADIAL CYLINDERINTERNAL COMBUSTIdN ENGINES Filed July 24, 1929 2 Sheets-Sheet l fad654W April 26, 1932.

A. H. R. FEDDEN 1,855,851 EXHAUST MANIFOLD FOR RADIAL CYLINDER INTERNALCOMBUSTION ENGINES Filed July 24, 1929 2 Sheets-Sheet 2 Jim/MM PatentedApr. 26, 1932 1 UNITED STATES PATENT OFFICE ALFRED HUBE'RT ROY FEDDEN, FBRISTOL, ENGLAND, ASSIGNOR TO THE BRISTOL AEROPLANE COMPANY LIMITED, 01BRISTOL, ENGLAND, A BRITISH COMPANY EXHAUST MANIFOLD FOR RADIAL-CYLINDERINZI'EIBLEI'AL-($0M BU'S'I'ION ENGINES Application filed July 24,

The object of this invention is to provide an improved construction ofexhaust manifold for a radial-cylinder internal-combustion engine suchas it used on aircraft.

It will be appreciated that the passage of hot exhaust gases through themanifold tends to overheat it; also, it is desirable that the exhaustgases should be collected and discharged from outlets which can beappropriately situated with respect to the machine wherein the engine ismounted: furthermore, owing to the heat developed in the engine and theheating of the exhaust manifold, provision must be made foraccommodating the relative thermal expansions.

In the accompanying drawings- Figure 1 is a sectional elevation showingthe improved exhaust manifold and its location on an engine;

Figure 2 is an elevation looking from the right-hand side in Figure 1;

Figures 3 and 4 are partial views of the manifold to a larger scale.

Referring first to Figures 1 and 2, the exhaust manifold for aradiaLcylinder internal-combustion engine is constituted by an annularchamber 10 which encircles the front portion of the crank-caseimmediately behind the propeller. Communicating with this chamber thereare a plurality of branch pipes 11 serving the various cylinders of theengine. Where each cylinder has two exhaustports, the branch pipe 11 maybe bifurcated as at 12, or if desired a pipe may communicate directlyfrom each exhaust-port in the cylmder to the chamber 10. The branchpipes11 are preferably so shapedadjacent the chamber 10 as to direct theexhaust gases 0 m a circumferential direction, and one or more outlets13 from the chamber 10 are provided at any convenient position.

In order to assist in the cooling of the exhaust manifold and the gasesin it, the cham- 5 her 10 is preferably of substantially tr angularcross-section as shown most clearly in Figures 1 and 3 with the apex ofthe triangle directed against he air-stream which flows into the spacewithin the chamber 10. In order to enhance the cooling eife'ct theairstream is caused to flow closely around the 1929. Serial No. 380,588.

vclosely over the walls of the chamber 10 whereby it is efl'ectivelycooled. The baflleplate terminates in a skirt 14' which leaves the outerportions of the cylinders unshielded, so that after leaving the space17, the an is allowed to flow on to the cylinders of'the "engine toeffect the cooling of these parts.

The conical outer and inner faces of the annular chamber 10 would beefiectively pooled by the air stream without the apphcation of thebaflle-plate 14, although in such case the inner or concave conicalsurface would receive a less concentrated flow of air than the exterioror convex conical surface; and the rear wall 15 would be very inade 7quately cooled. The particular shape given to the baffle-plate 14accomplishes two functions ;.first, by its inner annular portion beingmade to gradually approach the concave conical surface of the chamber10,1t concentrates the air stream and causes it to flow moreenergetically over this inner surface than it would otherwise do;thereby increasing the cooling effect against such surface; andsecondly, by being carried around the rear of the rear wall 15 andapproaching closely to this wall, it directs the air stream which hascirculated through the converging space 16 and thereby had its velocltyincreased and causes such concentrated stream to flow energetically overthe rear surface of the wall 15, whereby this surface is alsoeffectively cooled. Y

The exhaust manifold and the bafile-plate.

are secured together by suitable brackets '18,. 19, see Figure 3, andthey are supported on the crank-case of the engine by brackets y Inorder to accommodate the relatlve, movements of the parts of the exhaustmamfold and of the engine due to thermal expansion, eachbranch-pipe 11isprovided with a 'telescopic joint. As shown in Figure 3, the

part 21 of the branch-pipe has the flange 22 welded on it, and a similarco-operating flange 23 is welded on to an intermediate length of piping24 which overlaps by a considerable length the upper part'25 of thebranch-pipe 11. The parts 24 and 25 are a sliding fit one within theother so that the whole provides a telescopic construction. It will beappreciated, moreover, that since the parts are held together by boltsand nuts engaging the flanges 22, 23, the parts are readily" separablefor overhaul and maintenance Work on the engine.

7 A swivel joint is preferably also provided in each branch pipe nearits connection to the exhaust port. As shown in Figure 4, the end 26 ofthe pipe 12 is provided with a bellmouthed fitting 27 and a similar part28 is secured on the end 29 of the pine communicating with the exhaustport. The two parts 27, 28 are spaced apart and a ring-like member 30formed with conical ends co-operates with them, to provide a flexiblejoint. The joint is maintained by co-operating screwthreadedsleeves 31,32 in the manner ofan ordinary spigoted pipe-joint. A flexible joint ofthis nature permits a limited degree of relative movement in alldirections between the exhaust manifold and the cylinder so that inaddition to facilitating the fitting of the manifold, any movements dueto different expansions of the parts concerned are accommodated withoutdifiiculty.

I claim 1. An exhaust manifold for a radial-cylinder internal-combustionengine compris ing an annular chamber, a plurality of ranch pipescommunicating therewith and an annular bafile-plate which is enclosedwithin said chamber and extends behind it to direct a flow of coolingair over its surface.

2. An exhaust manifold for a radial-cylinder internal-combustion enginecomprising an, annular chamber, a plurality ofbranch-pipes communicatingtherewith and and an annular bafile plate which is enclosed within saidchamber and extends behind it to direct a flow'of cooling air over itssurface and having an annular skirt adapted to direct the air on to thecylinders of the engine.

3.-An exhaust manifold for a radial-cylinder internal-combustion enginercomprising an annular chamber, and a plurality'of branch pipes 'leadinthe exhaust from the cylinders thereto 88.51 provided with a telescopicJoint at its junctlon with the annular chamber.

4. An exhaust manifold for a radialcylinder internal-combustion enginecomprising an annular exhaust chamber and a plurality of. branch pipescommunicating therewith, the chamber tapered in cross-section so thatt's-'- lnner wall constitutes: a concave conical baflle-plate having aportion located within said annular chamber and approaching the lattermore closely at its rear than at its front, so' as to form a convergingair passage between, and said bafllelate extended outwardly andrearwardly 0 said annular chamber and approaching the latter at its rearmore closely than its approach to the inner face thereof, whereby toconcentrate the current of air against the rear wall of the annularchamber to effectually cool the latter. 1

In testimony whereof I afiix my signature.

ALFRED HUBERT ROY FEDDEN.

